You may find monasteries and meditation centres that offer meditation courses generally free of charge in the buddhist publication society guide lanka_monasteries_2008_jan.pdf.
Mahamevnawa Meditation Monastery
Is a good place to learn true buddhism.
There are many foreign enthusiasts to learn sri lankan traditional dance under three categories which are udarata, pahatharata and sabaragamu. and there are distinguished drumming for those categories.